Three British soldiers were killed in Afghanistan when an armoured vehicle introduced to protect troops was devastated by a huge roadside bomb.

Six other servicemen were injured - but escaped alive - when the Taliban blast hurled their 15-tonne Mastiff several metres into the air during a patrol in Helmand Province.

The explosion ripped through the personnel carrier, flipping it onto its roof as it crashed to the ground, while it travelled on a hard-top road five miles north of the provincial capital Lashkar Gah.

The trio were evacuated by air to the military hospital at Camp Bastion but could not be saved.

It is the first time troops have died in the Mastiff, brought in specifically to combat the threat of improvised explosive devices (IEDs) - responsible for killing 75 per cent of UK military personnel in the war.

Scroll down for video

Targeted: Three British soldiers were killed in Afghanistan when their Mastiff armoured vehicle which was introduced to protect troops was devastated by a huge roadside bomb (file picture)

It had already been announced that 170 soldiers would stay to run the Afghan officer academy at Qarga, known as 'Sandhurst in the sand' (file photo)

And it is the biggest single loss of
life inflicted by a buried bomb since six soldiers died when their
Warrior armoured vehicle struck an IED in March last year.

The deaths took the number of British
soldiers killed in Afghanistan to 444 since the conflict began
following the 9/11 attacks in 2001.

It came just three days after the Taliban launched its so-called 'Spring Offensive' against Coalition forces.

Share this article

Prime Minister David Cameron today said the UK had paid a 'very high price' for the work it was doing in country.

But speaking on ITV's Daybreak, he said that work was 'vital' in making sure the country 'doesn't again become a haven for terrorists'.

He added: 'Our thoughts should be with the families and friends of those that have suffered.'

Trusted: The heavily-armoured Mastiff, the newest in the range of protected patrol vehicles being used for UK operations, was introduced in 2009. Here, it is compared with the 'Snatch' Land Rover

The dead soldiers served with the Royal Highland Fusiliers, 2nd Battalion, the Royal Regiment of Scotland (2 SCOTS).

Their identities have not been released, but the Ministry of Defence said their next of kin had been informed.

Major Richard Morgan, spokesman for
Task Force Helmand, said: 'It is with deep sadness that I must confirm
that three soldiers from The Royal Highland Fusiliers, 2nd Battalion The
Royal Regiment of Scotland, have died after their vehicle was struck by
an improvised explosive device in the Nahr-e Saraj district of Helmand
Province.

'Their deaths come as a great loss to
all those serving in Task Force Helmand. Our thoughts and prayers are
extended to their family and friends at this difficult time.'

Scotland`s First Minister Alex Salmond said: 'This is tragic news and our thoughts and deepest sympathies are with the families and loved ones of the soldiers who have been lost.

'This incident demonstrates once again the dangers faced by our armed forces, often on a daily basis, and they deserve our deepest gratitude and respect for the job they do in some of the most difficult and trying circumstances imaginable.

'No words can truly bring comfort to the families at a time like this, but the thoughts and prayers of everyone in Scotland will be with them upon hearing this dreadful news.'

'Paying a high price': It is the biggest single loss of life inflicted by a buried bomb since six soldiers died when their Warrior armoured vehicle (above) struck an IED in March last year

About 350 soldiers from the Royal
Highland Fusiliers, 2nd Battalion The Royal Regiment of Scotland (2
SCOTS) were deployed to Afghanistan in March to start a six-month
operational tour of Helmand.

The battalion, based at Glencorse
Barracks in Penicuik, Midlothian, took over a number of roles including
mentoring and training Afghan National Security Forces, to help prepare
them for when Nato troops pull out next year.

They are advising Afghan police chiefs and assisting with the training of new officers.

Poppyscotland, which raises funds to
support ex-servicemen and women, posted on its Facebook page: 'We're
deeply saddened to hear that three members of the Royal Highland
Fusiliers, the 2nd Battalion The Royal Regiment of Scotland have been
killed in Afghanistan. Our thoughts are with their families and
colleagues.'

It was unclear last night whether the
explosion was caused by the British vehicle hitting the bomb or whether
it had been triggered by someone monitoring for the patrol. Officials
said they had not seen an increase in Taliban activity in the area.

Overdue: The MoD's other main armoured vehicle, the Warrior, was heavily criticised by a coroner five years ago for not having enough protection. Improvements were finally made in June 2011

The horrific incident happened around
midday Afghan time yesterday as the troops took part in a mission in the
district of Nahr-e Saraj South, an insurgent hotbed.

A convoy was understood to be helping
search for IEDs close to the border with Kandahar Province when the
blast struck one vehicle. The attack also killed nine Afghans.

The heavily-armoured Mastiff, the
newest in the range of protected patrol vehicles being used for UK
operations, was introduced in 2009.

Carrying two crew and eight troops,
the vehicles are trusted because no-one has been killed in them -
despite several striking roadside bombs.

A defence source said: 'A very big IED
struck the Mastiff, a huge one. The vehicle was thrown high up in the
air, overturned and came down the wrong way up.

'A very big IED
struck the Mastiff, a huge one. The vehicle was thrown high up in the
air, overturned and came down the wrong way up. It is a very well
protected vehicle, but if the insurgents build a bomb big enough they
can take anything out'

Defence source

'It is a very well protected vehicle, but if the insurgents build a bomb big enough they can take anything out.'

Major Chris Hunter, an author and
former British Army bomb disposal operator, said he was almost certain
that the bomb was in the category of 'bulk buried munitions' likely to
have been made up of between 100 to 200 kilos of high explosives.

'Any system can be overcome given
sufficient time, money and resources. What we have seen here, I am
almost certain, is bulk buried munitions, and that is exactly the
evolution we saw in Iraq,' he said.

'We have seen this employed elsewhere
in Afghanistan but we have not seen it deployed against a Mastiff
armoured vehicle to date.'

He said the risks to insurgents of planting such a large bomb were high.

'It takes such a long time to do and
the risk to the perpetrators is so high that it is not something we will
see as a regular occurrence,' he said.

'Obviously in Afghanistan we always see a quiet period during the winter months and then a spring offensive begins in earnest.

'I think what we have seen is a
significant incident to mark the beginning of the spring offensive but
we are not going to see it as a regular occurrence because I think it is
just too high a risk to the Taliban.'

Scene: The soldiers were on a routine patrol in the Nahr-e Saraj district of Helmand Province

The Taliban last night claimed
responsibility for the attack, threatening to step-up bombings against
Coalition troops in the 'coming months'.

The insurgents warned they would
infiltrate enemy ranks to conduct 'insider attacks' and target military
and diplomatic sites with suicide bombers.

In past years, spring has marked a
significant upsurge in fighting between the Taliban and NATO forces
along with their local allies. This fighting season is a key test,
however, as the international coalition is scheduled to hand over
security responsibilities to Afghan forces next year.

UK forces have dramatically cut back
on foot patrols in recent months remaining mostly in their bases while
Afghan troops have taken over the role as the British soldiers prepare
for the withdrawal of thousands of servicemen and women next year.

The change of operational policy has
led to a significant reduction in casualties. Until yesterday, three
servicemen had died this year in Afghanistan compared to 15 in the same
period in 2012 and 16 in the first four months of 2011.

Each mission of a 'fighting patrol' now has to be cleared high up the chain of command.

'Any system can be overcome given
sufficient time, money and resources. What we have seen here, I am
almost certain, is bulk buried munitions, and that is exactly the
evolution we saw in Iraq'

Major Chris HunterFormer British Army bomb disposal operator

However, vehicle patrols such as the one yesterday by UK troops on main roads have continued.

The British deaths come a day after
seven crew were killed when a U.S. civilian cargo plane crashed at
Bagram airbase, near the Afghan capital Kabul.

It also came just two weeks after the
new brigade arrived in southern Afghanistan for what is expected to be
the last bloody summer offensive.

Commanded by Brigadier Rupert Jones,
the son of Colonel 'H' Jones who won the Victoria Cross at Goose Green
in 1982, his soldiers of 1st Mechanized Brigade officially took command
on 10th April.

The formation which has the Rifles,
Royal Highland Fusiliers, Duke of Lancasters and Royal Regiment of
Scotland as its lead infantry units, is expected to serve a longer tour
as units prepare to pull out.

The Royal Highland Fusiliers are split
across Helmand and have a company based in Nahr-e Saraj, a mortar
platoon based in Lashkar Gah and they also run the Lashkar Gah Police
training centre.

As the UK Area of Operation decreases
with the handover of Forward Operating Bases to Afghan Security Forces,
the number of bases occupied by British troops has reduced from 37 to
12.

Meanwhile, in another attack in the
south of the country, a roadside bomb in the Shah Wali Kot district of
Kandahar province killed three civilians and wounded five.

And in Archi district in the province
of Kunduz, a roadside bomb killed two people, including a local police
commander who had been credited with reducing the number of insurgent
attacks in his area.

Britain's 444 victims of 12-year battle with Taliban insurgents

A total of 444 British troops have been killed in Afghanistan since Western forces invaded the country in 2001 in response to the September 11 attacks.

In addition, more than 2,000 American troops and over 600 soldiers from other countries in the Nato coalition have died as a result of fighting with the Taliban.

The latest deaths bring the total of British casualties in 2013 so far to six, all in the dangerous Helmand Province which is often considered a Taliban stronghold.

Blown up: The deaths of (top row left to right) Sergeant Nigel Coupe, Corporal Jake Hartley, Private Anthony Frampton and (bottom row left to right) Private Christopher Kershaw, Private Daniel Wade and Private Daniel Wilford in March last year was the biggest-ever single loss at the hands of insurgents

Sapper Richard Walker was killed in January in a 'blue on green' attack from a rogue member of the Afghan National Army.

Kingsman David Shaw died weeks later when his checkpoint came under fire from insurgents - he was airlifted back to the UK for hospital treatment, but did not survive.

In March, L/Cpl Jamie Webb, 24, from Wythenshawe, Greater Manchester, died after an attack by Taliban militants in the Nad-e Ali district of Helmand.

Last year, six British servicemen were killed when a roadside bomb struck their armoured vehicle.

The attack was the worst single loss of life for UK troops in Afghanistan since a Nimrod crash killed 14 in 2006.